This invention relates to an improved heat shield to be positioned between a housing end cap and a non-orbiting scroll wherein a seal is provided by structure on the end cap.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a scroll compressor a first scroll member has a base and a generally spiral wrap extending from its base. A second scroll member also has a base and a generally spiral wrap extending from its base. The two wraps interfit to define compression chambers. The second scroll member is driven to orbit relative to the first scroll member and the size of the compression chambers is decreased, compressing an entrapped refrigerant.
In a scroll compressor, the refrigerant being compressed is often passed over the electric motor when entering the compressor through a suction tube. This flow of suction refrigerant cools the motor. However, flowing the suction refrigerant over the motor requires that there be a seal within the compressor housing between a discharge chamber and a suction chamber. Typically, some separator plate has been incorporated extending across the interior of the compressor housing to define both a suction and discharge chamber.
More recently, scroll compressors have been developed which do not utilize a separator plate, but instead separates the discharge and suction chambers through the structure of the first scroll member described above. With such an application, it becomes desirable to provide a heat insulating structure between the non-orbiting scroll and the discharge chamber. Thus, a heat shield has been proposed in co-pending patent application Ser. No. 09/451306 filed Nov. 29, 1999.
While such a compressor has proven quite successful, it would be desirable to improve upon this structure, and in particular, utilize the heat shield in conjunction with the non-orbiting scroll and a housing end cap to provide a seal.
In the disclosed embodiment of this invention, the heat shield has a downwardly extending portion which is non-cylindrical such that it will contact both the non-orbiting scroll and the end cap of the housing to provide an adequate seal between the discharge chamber and the suction chamber. In one embodiment, the end portion of the heat shield is serpentine, or generally s-shaped, such that portions of the heat shield will contact the outer periphery of the non-orbiting scroll, and another portion will contact the inner periphery of the end cap. When the housing members are brought together, the connection ensures adequate sealing between the discharge and suction chambers.
In another embodiment, the end portion is generally u-shaped. Again, when the housing members are brought together, there will be an adequate seal between the inner periphery of the end cap and the outer periphery of the non-orbiting scroll.
In other embodiments, the end portion extends radially outwardly and circumferentially around the heat shield. In one embodiment, there is a raised rib that will be squeezed between the upper shell and the non-orbiting scroll. In another embodiment, the edge is wrapped back radially inwardly to provide the sealing portion. In yet another embodiment, a sealing material is bonded to the radially outer portion.
In further embodiments, the heat shield has inwardly extending clip portions which fit into a groove on the outer periphery of the non-orbiting scroll. This structure positions the heat shield at a desired position on the non-orbiting scroll ensuring that the end cap and non-orbiting scroll together compress the heat shield to achieve a seal between the discharge and pressure chambers. In one embodiment this seal is provided by the heat shield, while in another embodiment the seal is provided between the non-orbiting scroll and the end cap.
Several other embodiments are also included. In some embodiments, the heat shield has a inwardly extending u-shaped portion fitting into a groove within the non-orbiting scroll. In another embodiment, the heat shield has a generally radially outwardly extending portion which is bent axially downwardly by the end cap. In yet another embodiment, there is a generally u-shaped portion on the heat shield extending axially into a ditch in the non-orbiting scroll, and then a radially outer portion extending from the u-shaped portion.
In further embodiments, there are ribs on either the non-orbiting scroll, or the heat shield. The ribs will provide a crush point to provide a seal. The ribs are placed in various locations on the two elements.
In further embodiments, the heat shield has an upwardly extending portion which abuts an inner end of the end cap. In yet another embodiment, the heat shield has a radially outwardly extending portion which extends to an axially lower portion fitting into a groove in the non-orbiting scroll. In yet another embodiment, a radially outer portion of the heat shield is deformed axially downwardly by the end cap. In many of the embodiments, there may also be resilient material added to the sealing portion of the heat shield.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.